Gov. Jerry Brown has just signed a complex bill that will change the way that residential electricity rates are figured in California - and hopefully pave the way for more people to get access to solar energy.

The bill, AB327, won't make everyone happy.

But the measure tackles a complicated issue, and it's the end result of months of negotiations and revisions. It could never make everyone happy, but what's most important is that it protects consumers and underlines California's commitment to renewable energy.

On the latter point, AB327 is a definite winner.

The bill protects and expands "net metering," a popular program that allows homeowners, businesses and school districts that have rooftop solar panels to run their electricity meters backward when their solar panels are feeding excess energy into the electrical grid. Current state law requires major utilities to make net metering available, but only up to 5 percent of a utility's "aggregate customer peak demand." San Francisco's PG&E has more than 90,000 net-metering customers in Northern California.

AB327 will authorize the California Public Utilities Commission to create new net metering regulations after that 5 percent cap has been reached. The PUC hasn't made the regulations yet, but they're widely considered to lead to an expansion of net metering beyond the cap - and that's a big win for the solar industry and solar enthusiasts. Net metering is one of the major benefits of installing solar, which can be quite expensive. Opening it up will surely encourage new customers to buy solar.

All of this is great news. But there's a catch, of course.

The three major utilities aren't coming out of this empty-handed. They've long complained that solar customers using net metering aren't paying for the costs to transmit energy - and now they may have found a way to make sure that every customer, solar or not, will have to pay for transmission costs.

Under AB327, the PUC will also gain the authority to implement a monthly surcharge of up to $10 per customer and $5 per low-income customer. The PUC expects to come to a decision on those charges sometime next year, following the usual public comment process.

The PUC says that the change won't necessarily mean that your monthly bill will go up; the fixed charge would come with a shift in electricity assessment as well.

"If you implement a fixed charge, it's likely that the volume rate goes down," said Edward Randolph, energy director for the PUC. "What's important about the fixed charge for those who advocate for it is that it helps us get closer to the principle that everyone pays for the fixed costs of their energy transmissions."

Consumer groups are already getting nervous about a new charge, and rightfully so. Gov. Jerry Brown instructed the PUC to protect those customers who already have solar when creating the new regulations for net metering. But when it comes to new utility charges, the PUC needs to protect all of us.